On Tue, Aug 21, 2012 at 04:22:31PM +0400, Pavel Emelyanov wrote: > On 08/21/2012 04:11 PM, J. Bruce Fields wrote: > > On Tue, Aug 21, 2012 at 03:09:05PM +0400, Pavel Emelyanov wrote: > >> On 08/21/2012 02:54 PM, Cyrill Gorcunov wrote: > >>> On Tue, Aug 21, 2012 at 02:49:47PM +0400, Pavel Emelyanov wrote: > >>>>>> > >>>>>> However, if you have some better ideas on what information about inode should be exported > >>>>>> to the userspace please share. > >>>>>> > >>>>> > >>>>> Why not use name_to_handle(fd,...) and open_by_handle(handle,..) ? > >>>> > >>>> Because we don't have an fd at hands by the time we need to know the handle. > >>> > >>> Yeah, this might be not clear from patchset itself but inotify marks carry > >>> inodes inside kernel thus it's inodes what we can use when we fetch information > >>> about targets and put it into fdinfo output. > >> > >> Al, Bruce, Aneesh, > >> > >> What if we calculate the handle at the time we do have struct path at hands (i.e. > >> when we create the inotify) and store it on the inotify structure purely to be > >> shown later in proc. Would that be acceptable? > > > > Was it the lack of a dentry that was really the problem? I thought it > > was just the fact that not all filesystems support filehandles. > > Initial problem -- we don't know what is being watched by an inotify fd. > > Having a dentry somewhere was the 1st attempt to solve this -- keep a path > in inotify and show it when required. It doesn't work since holding a ref on > path changes the behavior of watched inode (we cannot rename/unlink/remount > it the same way as we could before patching the kernel). OK. So if you don't mind the fact that there are filesystems with inotify support but not filehandle support, then I think generating a filehandle early as you describe would work. I guess it's a little more memory per watched inode. --b. -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
